Clutch.



CLUTCH.

(Application led Mar. 14, 1902.)

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CLUTCH.

(Appiication mea nu. 14, 1902.) (lo lModel.) 2 Sheets-Sheet I2.'

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UNITED STATES PATENT OFFICE.

FRANK S. HAWKINS, OF BOSTON, MASSACHUSETTS.

CLUTCH.

SPECIFICATION forming part of Letters Patent No. 712,133, dated October 28, 1902. Application filed March 14, 1902. Serial No. 98,253. (No model.)

To a/ZZ whom it may concern.-

Be it known that I, FRANK S. HAWKINS, of Boston, in the county of Suffolk and State of Massachusetts, have invented a new and use- 5 ful Improvement in Clutches, of which the l following, taken in connection with the accompanying drawings, is a specification.

My invention relates to a self-engaging friction-clutch; and it consists in combining with a driving-pulley loosely mounted on the main shaft a fixed friction-disk at one end of the said driving-pulley and a loose friction-disk at the other end, the loose friction-disk hav-l ing upon its outer side a series of ratchetteeth adapted to engage with and slide upon a. similar set of teeth made upon the face of,

a fixed hub. The loose friction-disk is free to move a short distance longitudinally-upon the said main shaft. The rotary motion of the loose friction-disk is limited by the contact of the ratchet-teeth and is caused by the action of a spring.

The operation of my clutch may be best understood by reference to the specification and the accompanying drawings. The said drawings are as follows:

Figure l is an elevation showing a part of the main shaft, a driving-pulley, and the clutch device. Fig. 2 is an end elevation of the same. Fig. 3 is a central longitudinal section of the pulley and its clutch, showing the shaft in elevation.

In the drawings, A represents the main shaft, and B a driving-pulley loosely mounted upon it.

C is a friction-disk pinned, as shown at C', or otherwise secured to the shaft A and having its working face-that is, the face that is next to the end of the pulley B-covered with leather or some other suitable material that will wear well as a friction-surface. A second friction-disk D is placed upon the main shaft and adapted to act frictionally upon the other end of the pulley B. The friction-disk D has a hub D', which has upon its-face inclined notches, as indicated at D D2, which correspond and engage with similar notches E2 on the hub E, which is pinned to the main shaft. A helical spring S surrounds the two hubs 5o and has one of its ends made fast to the hub E at S and its other end made fast to the hub of the friction-disk D at S2. The tendency of the spring S is to cause the friction-diskD to rotate in the direction Iof the arrow H. This action of rotation relatively between the hubs will cause the inclines to act upon each other, and thus force the friction disk D against the end of the pulley B and to cause the said pulley to be forced against the other friction-disk C, thus bringing a frictional action against both ends of the pulley B. In

other words, the pulley is clamped between two endwise-acting friction-disks. Besides the endwise clampingy action caused by the spring S anotherforce acts, which may be explained as follows: We suppose the belt on the kpulleyB drives the pulley in the direction of the arrow Pand that the resistance due to the work required of the shaft has a tendency to hold it back. These two forces work together to force-the inclines on the two hubs to slide upon each other, thus forcing the friction-disk D against the end of thepulley B and in turn the pulley itself against ythe disk C, thus causing an additional friction on said pulley, so that there is no possible chance that the pulley will slip on its shaft.

Fromthe above it will be seen that the action of this clutch is largely automatic-that is, if left to itself it will remain in engagement.

It is not absolutely necessary that the disk C be a friction-disk, as a collar in its place fixed to the main shaft to prevent the pulley B'from sliding too far would serve the purpose, though not so well.

To disengage or th'row the clutch out of action, I have the bent lever L L,which is pivoted at L2 and operated by the rod or chain L2. The action of this lever is to force the disk D away from the end of the pulley by simply checking its motion of rotation, so that the inclines on the two hubs will slide back and allow the disk D to be forced away from the end of the pulley B, lthus leaving the pulley free to rotate on the shaft A.

l. A clutch device comprisingA a looselyrunning driving-pulley on the main shaft; a fixed friction-disk on the said shaft, and adapted to engage frictionally with one end of the said pulley; a moving friction-disk on said shaft adapted to engage with the other end of said pulley, and having a hub with in- IOO olines', adapted to engage with similar inclines, made on a fixed hub; said fixed hub; a spring adapted to cause a relative rotative motion between said fixed hub and said moving frction-disk,wl1ereby the clutch is thrown into engagement; a lever adapted to frictionally engage with the said moving frictiondisk, thereby checking its motion and forcing it back out of contact with the pulley, substantially as and for the purpose set forth.

2. A clutch device, comprising a looselyrunning driving-pulley on the main shaft; means at one kend of said driving-pulley on said main shaft, adapted to prevent longitudinal motion of said driving-pulley; a moving friction-disk on said shaft adapted to engage with the other end of the said pulley, and having a hub with inclines, adapted to engage with similar inclines made on a fixed hub; said fixed hub; a spring adapted to cause a relative rotative motion between said fixed hub and said moving friction-disk, whereby the clutch is thrown into engagement; a lever adapted to frictionally engage with the said moving friction-disk, thereby checking its motion and forcing it back out of contact with the pulley, substantially as and for the purpose set forth.

In testimony whereof I have signed my name to this specification, in the presence of two subscribing witnesses, this 12th day of March, A. D. 1902.

FRANK S. HAWKINS.

Witnesses:

ANNA C, KINGSBURY, WILLrAM EDSON. 

